Rolling bearings having braking devices have long been known. There is a risk with rolling bearing rotational connections on wind power stations, for example, that they will fail after a relatively short time due to furrowing in the raceways. This phenomenon is produced due, in particular, to slight pivoting movements in order to compensate for the wind direction, during which the rolling bodies slide on the raceway. In order to preclude this wear, various measures are known for increasing the low rotational resistance in rolling bearings. DE 37 25 972 A1 and DE 41 04 137 A1 in this context propose to use an additionally rotating braking device. The braking force and hence the desired rotational resistance can then be externally adjusted. The disadvantage to this in the first case is that the braking element can be cancelled only when the wind power station is shut down. In the second case the braking device comprises many mechanical components making it complex to manufacture and complicated to handle.
DE 19 04 954 B discloses a pivotless rotational connection for excavators, cranes or the like for supporting a rotatable superstructure on a substructure. These rotational connections in each case comprise a one-part swivel ring and a further, two-part swivel ring assembled from two profile rings. The two swivel rings are each braced against one another by the balls of a double-row ball bearing and are equipped with a braking device. The braking devices each have one or more brake shoe carriers, which are attached to a component connected to the one-part swivel ring. A disadvantage with this arrangement is that the braking devices are located outside the actual bearing arrangement and therefore take up additional installation space.
A bearing arrangement of generic type with braking function has been previously disclosed by DE 101 27 487 A1. The radial bearing arrangement according to FIG. 1 has a deep-groove ball bearing embodied as a radial bearing and a braking device located axially next to this. The deep-groove ball bearing comprises the inner race, the outer race and bearing balls arranged in a cage between them. The deep-groove ball bearing furthermore comprises two sealing rings, which seal off the annular space from the surroundings on both sides. The braking device has an inner retaining ring and an outer retaining ring. Fixed to a radially outward-facing flange of the inner retaining ring by way of a flat wire spring is a brake disk, which is composed of a ferromagnetic material and has a brake lining on its side remote from the flange. The brake disk is rotationally locked to the inner retaining ring by way of the flat wire spring fastening and is displaceable in an axial direction. Opposite the brake lining, an opposing face, against which the brake lining is pressed during braking, is formed on the outer retaining ring. The outer retaining ring furthermore has an electrical coil and one or more permanent magnets, which are each arranged in the area between the brake disk and the deep-groove ball bearing and are mechanically connected to the outer retaining ring and consequently also to the opposing face.
A disadvantage to this is that the braking device has to be flanged in an axial direction onto the bearing as an external component and therefore takes up additional installation space. The retaining rings are of relatively complicated construction and first have to be connected in a complex manner to the bearing races with pins. A further disadvantage is that the braking effect is initiated by a permanent magnet, which attracts the brake disk. In certain applications, however, a constant magnetic field is detrimental, since iron-containing dirt is possibly attracted by the bearing.